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core, testpico fixes

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This commit is contained in:
kub 2023-06-09 19:22:51 +00:00
parent 3d7abd6905
commit f61d0a4534
3 changed files with 33 additions and 12 deletions
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31
pico/memory.c
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@ -1039,10 +1039,24 @@ static void m68k_mem_setup(void)
static int get_scanline(int is_from_z80)
{
if (is_from_z80) {
int mclk_z80 = (z80_cyclesLeft<0 ? Pico.t.z80c_aim : z80_cyclesDone()) * 15;
int mclk_line = Pico.t.z80_scanline * 488 * 7;
while (mclk_z80 - mclk_line >= 488 * 7)
Pico.t.z80_scanline++, mclk_line += 488 * 7;
// ugh... compute by dividing cycles since frame start by cycles per line
// need some fractional resolution here, else there may be an extra line
int cycles_line = cycles_68k_to_z80(488 << 8); // cycles per line, as Q8
int cycles_z80 = (z80_cyclesLeft<0 ? Pico.t.z80c_aim:z80_cyclesDone())<<8;
int cycles = cycles_line * Pico.t.z80_scanline;
// approximation by multiplying with inverse
if (cycles_z80 - cycles >= 2*cycles_line) {
// compute 1/cycles_line, storing the result to avoid future dividing
static int cycles_line_o, cycles_line_i;
if (cycles_line_o != cycles_line)
{ cycles_line_o = cycles_line, cycles_line_i = (1<<22) / cycles_line; }
// compute lines = diff/cycles_line = diff*(1/cycles_line)
int lines = ((cycles_z80 - cycles) * cycles_line_i) >> 22;
Pico.t.z80_scanline += lines, cycles += cycles_line * lines;
}
// handle any rounding leftover
while (cycles_z80 - cycles >= cycles_line)
Pico.t.z80_scanline ++, cycles += cycles_line;
return Pico.t.z80_scanline;
}
@ -1342,7 +1356,8 @@ void PicoWrite16_32x(u32 a, u32 d) {}
static unsigned char z80_md_vdp_read(unsigned short a)
{
if ((a & 0xff00) == 0x7f00) {
z80_subCLeft(3);
static int f; f = (f&0xff) + 0x8c; // 0.6
z80_subCLeft(2+(f>>8)); // 3.3 per kabuto, but notaz' test implies 2.6 ?!?
Pico.t.z80_buscycles += 7;
switch (a & 0x0d)
@ -1368,9 +1383,10 @@ static unsigned char z80_md_bank_read(unsigned short a)
unsigned char ret;
// account for 68K bus access on both CPUs.
static int f; f = (f&0xff) + 0x4c; // 0.3
z80_subCLeft(3+(f>>8)); // 3.3 per kabuto
// don't use SekCyclesBurn(7) here since the Z80 doesn't run in cycle lock to
// the 68K. Count the stolen cycles to be accounted later in the 68k CPU runs
z80_subCLeft(3);
Pico.t.z80_buscycles += 7;
addr68k = Pico.m.z80_bank68k << 15;
@ -1413,9 +1429,10 @@ static void z80_md_bank_write(unsigned int a, unsigned char data)
unsigned int addr68k;
// account for 68K bus access on both CPUs.
static int f; f = (f&0xff) + 0x4c; // 0.3
z80_subCLeft(3+(f>>8)); // 3.3 per kabuto
// don't use SekCyclesBurn(7) here since the Z80 doesn't run in cycle lock to
// the 68K. Count the stolen cycles to be accounted later in the 68K CPU runs
z80_subCLeft(3);
Pico.t.z80_buscycles += 7;
addr68k = Pico.m.z80_bank68k << 15;

2
pico/pico_int.h
View file

@ -205,7 +205,7 @@ extern struct DrZ80 drZ80;
(Pico.t.z80c_aim - z80_cyclesLeft)
// one line has 488 68K cycles and 228 Z80 cycles, 228/488*8192=3827
#define cycles_68k_to_z80(x) ((x) * 3857 >> 13)
#define cycles_68k_to_z80(x) ((x) * 3847 >> 13)
// ----------------------- SH2 CPU -----------------------

12
pico/videoport.c
View file

@ -17,7 +17,8 @@ enum { clkdiv = 2 }; // CPU clock granularity: one of 1,2,4,8
// VDP Slot timing, taken from http://gendev.spritesmind.net/
// forum/viewtopic.php?f=22&t=851&sid=d5701a71396ee7f700c74fb7cd85cb09
// Thank you very much for the great work, Nemesis!
// http://plutiedev.com/mirror/kabuto-hardware-notes
// Thank you very much for the great work, Nemesis, Kabuto!
// Slot clock is sysclock/20 for h32 and sysclock/16 for h40.
// One scanline is 63.7us/63.5us (h32/h40) long which is 488.6/487.4 68k cycles.
@ -30,13 +31,15 @@ enum { slcpu = 488 };
// is generated also depends on the video mode.
enum { hint32 = 0x85, gapstart32 = 0x94, gapend32 = 0xe9};
enum { hint40 = 0xa5, gapstart40 = 0xb7, gapend40 = 0xe5};
// XXX Kabuto says gapend40 is 0xe4, but then a line would've 211 slots, while
// it's 210 in all other sources I looked at?
// The horizontal sync period (HBLANK) is 30/37 slots (h32/h40):
// h32: 4 slots front porch (1.49us), 13 HSYNC (4.84us), 13 back porch (4.84us)
// h40: 5 slots front porch (1.49us), 16 HSYNC (4.77us), 16 back porch (4.77us)
// HBLANK starts in slot 0x93/0xb4, according to Nemesis' measurements.
// HBLANK starts in slot 0x93/0xb3 and ends after slot 0x05 (from Kabuto's doc)
enum { hboff32 = 0x93-hint32, hblen32 = 0xf8-(gapend32-gapstart32)-hint32};//30
enum { hboff40 = 0xb4-hint40, hblen40 = 0xf8-(gapend40-gapstart40)-hint40};//37
enum { hboff40 = 0xb3-hint40, hblen40 = 0xf8-(gapend40-gapstart40)-hint40};//37
// number of slots in a scanline
#define slots32 (0x100-(gapend32-gapstart32)) // 171
@ -1030,7 +1033,8 @@ static u32 VideoSr(const struct PicoVideo *pv)
{
unsigned int hp = pv->reg[12]&1 ? hboff40*488/slots40 : hboff32*488/slots32;
unsigned int hl = pv->reg[12]&1 ? hblen40*488/slots40 : hblen32*488/slots32;
unsigned int c = SekCyclesDone() - Pico.t.m68c_line_start;
// XXX -2 is to please notaz' testpico, but why is this?
unsigned int c = SekCyclesDone()-2 - Pico.t.m68c_line_start;
u32 d;
PicoVideoFIFOSync(c);